package com.gitee.wsl.collections.map.api


/**
 * Defines a map that allows bidirectional lookup between key and values.
 *
 *
 * This extended `Map` represents a mapping where a key may
 * lookup a value and a value may lookup a key with equal ease.
 * This interface extends `Map` and so may be used anywhere a map
 * is required. The interface provides an inverse map view, enabling
 * full access to both directions of the `BidiMap`.
 *
 *
 *
 * Implementations should allow a value to be looked up from a key and
 * a key to be looked up from a value with equal performance.
 *
 *
 *
 * This map enforces the restriction that there is a 1:1 relation between
 * keys and values, meaning that multiple keys cannot map to the same value.
 * This is required so that "inverting" the map results in a map without
 * duplicate keys. See the [.put] method description for more information.
 *
 *
 * @param <K> the type of the keys in the map
 * @param <V> the type of the values in the map
 * @since 3.0
</V></K> */
interface BidiMap<K, V> : MutableMap<K, V> {
    /**
     * Gets the key that is currently mapped to the specified value.
     *
     *
     * If the value is not contained in the map, `null` is returned.
     *
     *
     *
     * Implementations should seek to make this method perform equally as well
     * as `get(Object)`.
     *
     *
     * @param value  the value to find the key for
     * @return the mapped key, or `null` if not found
     * @throws ClassCastException (optional) if the map limits the type of the
     * value and the specified value is inappropriate
     * @throws NullPointerException (optional) if the map limits the values to
     * non-null and null was specified
     */
    fun getKey(value: V): K?

    /**
     * Gets a view of this map where the keys and values are reversed.
     *
     *
     * Changes to one map will be visible in the other and vice versa.
     * This enables both directions of the map to be accessed as a `Map`.
     *
     *
     *
     * Implementations should seek to avoid creating a new object every time this
     * method is called. See `AbstractMap.values()` etc. Calling this
     * method on the inverse map should return the original.
     *
     *
     * @return an inverted bidirectional map
     */
    fun inverseBidiMap(): BidiMap<V, K>

    /**
     * Puts the key-value pair into the map, replacing any previous pair.
     *
     *
     * When adding a key-value pair, the value may already exist in the map
     * against a different key. That mapping is removed, to ensure that the
     * value only occurs once in the inverse map.
     *
     * <pre>
     * BidiMap map1 = new DualHashBidiMap();
     * map.put("A","B");  // contains A mapped to B, as per Map
     * map.put("A","C");  // contains A mapped to C, as per Map
     *
     * BidiMap map2 = new DualHashBidiMap();
     * map.put("A","B");  // contains A mapped to B, as per Map
     * map.put("C","B");  // contains C mapped to B, key A is removed
    </pre> *
     *
     * @param key  the key to store
     * @param value  the value to store
     * @return the previous value mapped to this key
     * @throws UnsupportedOperationException if the `put` method is not supported
     * @throws ClassCastException (optional) if the map limits the type of the
     * value and the specified value is inappropriate
     * @throws IllegalArgumentException (optional) if the map limits the values
     * in some way and the value was invalid
     * @throws NullPointerException (optional) if the map limits the values to
     * non-null and null was specified
     */
     override fun put(key: K, value: V): V?

    /**
     * Removes the key-value pair that is currently mapped to the specified
     * value (optional operation).
     *
     *
     * If the value is not contained in the map, `null` is returned.
     *
     *
     *
     * Implementations should seek to make this method perform equally as well
     * as `remove(Object)`.
     *
     *
     * @param value  the value to find the key-value pair for
     * @return the key that was removed, `null` if nothing removed
     * @throws ClassCastException (optional) if the map limits the type of the
     * value and the specified value is inappropriate
     * @throws NullPointerException (optional) if the map limits the values to
     * non-null and null was specified
     * @throws UnsupportedOperationException if this method is not supported
     * by the implementation
     */
    fun removeValue(value: V): K?

    /**
     * Returns a [Set] view of the values contained in this map.
     * The set is backed by the map, so changes to the map are reflected
     * in the set, and vice-versa.  If the map is modified while an iteration
     * over the set is in progress (except through the iterator's own
     * `remove` operation), the results of the iteration are undefined.
     * The set supports element removal, which removes the corresponding
     * mapping from the map, via the `Iterator.remove`,
     * `Collection.remove`, `removeAll`,
     * `retainAll` and `clear` operations.  It does not
     * support the `add` or `addAll` operations.
     *
     * @return a set view of the values contained in this map
     */
    //fun values(): Set<V>
    override val values: MutableSet<V>
}
